diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_tc_tunnel.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_tc_tunnel.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_tc_tunnel.c b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c new file mode 100644 index 000000000000..74370e7e286d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_tc_tunnel.c @@ -0,0 +1,536 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* In-place tunneling */ + +#include <stdbool.h> +#include <string.h> + +#include <linux/stddef.h> +#include <linux/bpf.h> +#include <linux/if_ether.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/mpls.h> +#include <linux/tcp.h> +#include <linux/udp.h> +#include <linux/pkt_cls.h> +#include <linux/types.h> + +#include "bpf_endian.h" +#include "bpf_helpers.h" + +static const int cfg_port = 8000; + +static const int cfg_udp_src = 20000; + +#define UDP_PORT 5555 +#define MPLS_OVER_UDP_PORT 6635 +#define ETH_OVER_UDP_PORT 7777 + +/* MPLS label 1000 with S bit (last label) set and ttl of 255. */ +static const __u32 mpls_label = __bpf_constant_htonl(1000 << 12 | + MPLS_LS_S_MASK | 0xff); + +struct gre_hdr { + __be16 flags; + __be16 protocol; +} __attribute__((packed)); + +union l4hdr { + struct udphdr udp; + struct gre_hdr gre; +}; + +struct v4hdr { + struct iphdr ip; + union l4hdr l4hdr; + __u8 pad[16]; /* enough space for L2 header */ +} __attribute__((packed)); + +struct v6hdr { + struct ipv6hdr ip; + union l4hdr l4hdr; + __u8 pad[16]; /* enough space for L2 header */ +} __attribute__((packed)); + +static __always_inline void set_ipv4_csum(struct iphdr *iph) +{ + __u16 *iph16 = (__u16 *)iph; + __u32 csum; + int i; + + iph->check = 0; + +#pragma clang loop unroll(full) + for (i = 0, csum = 0; i < sizeof(*iph) >> 1; i++) + csum += *iph16++; + + iph->check = ~((csum & 0xffff) + (csum >> 16)); +} + +static __always_inline int encap_ipv4(struct __sk_buff *skb, __u8 encap_proto, + __u16 l2_proto) +{ + __u16 udp_dst = UDP_PORT; + struct iphdr iph_inner; + struct v4hdr h_outer; + struct tcphdr tcph; + int olen, l2_len; + int tcp_off; + __u64 flags; + + /* Most tests encapsulate a packet into a tunnel with the same + * network protocol, and derive the outer header fields from + * the inner header. + * + * The 6in4 case tests different inner and outer protocols. As + * the inner is ipv6, but the outer expects an ipv4 header as + * input, manually build a struct iphdr based on the ipv6hdr. + */ + if (encap_proto == IPPROTO_IPV6) { + const __u32 saddr = (192 << 24) | (168 << 16) | (1 << 8) | 1; + const __u32 daddr = (192 << 24) | (168 << 16) | (1 << 8) | 2; + struct ipv6hdr iph6_inner; + + /* Read the IPv6 header */ + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph6_inner, + sizeof(iph6_inner)) < 0) + return TC_ACT_OK; + + /* Derive the IPv4 header fields from the IPv6 header */ + memset(&iph_inner, 0, sizeof(iph_inner)); + iph_inner.version = 4; + iph_inner.ihl = 5; + iph_inner.tot_len = bpf_htons(sizeof(iph6_inner) + + bpf_ntohs(iph6_inner.payload_len)); + iph_inner.ttl = iph6_inner.hop_limit - 1; + iph_inner.protocol = iph6_inner.nexthdr; + iph_inner.saddr = __bpf_constant_htonl(saddr); + iph_inner.daddr = __bpf_constant_htonl(daddr); + + tcp_off = sizeof(iph6_inner); + } else { + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner, + sizeof(iph_inner)) < 0) + return TC_ACT_OK; + + tcp_off = sizeof(iph_inner); + } + + /* filter only packets we want */ + if (iph_inner.ihl != 5 || iph_inner.protocol != IPPROTO_TCP) + return TC_ACT_OK; + + if (bpf_skb_load_bytes(skb, ETH_HLEN + tcp_off, + &tcph, sizeof(tcph)) < 0) + return TC_ACT_OK; + + if (tcph.dest != __bpf_constant_htons(cfg_port)) + return TC_ACT_OK; + + olen = sizeof(h_outer.ip); + l2_len = 0; + + flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV4; + + switch (l2_proto) { + case ETH_P_MPLS_UC: + l2_len = sizeof(mpls_label); + udp_dst = MPLS_OVER_UDP_PORT; + break; + case ETH_P_TEB: + l2_len = ETH_HLEN; + udp_dst = ETH_OVER_UDP_PORT; + break; + } + flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len); + + switch (encap_proto) { + case IPPROTO_GRE: + flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE; + olen += sizeof(h_outer.l4hdr.gre); + h_outer.l4hdr.gre.protocol = bpf_htons(l2_proto); + h_outer.l4hdr.gre.flags = 0; + break; + case IPPROTO_UDP: + flags |= BPF_F_ADJ_ROOM_ENCAP_L4_UDP; + olen += sizeof(h_outer.l4hdr.udp); + h_outer.l4hdr.udp.source = __bpf_constant_htons(cfg_udp_src); + h_outer.l4hdr.udp.dest = bpf_htons(udp_dst); + h_outer.l4hdr.udp.check = 0; + h_outer.l4hdr.udp.len = bpf_htons(bpf_ntohs(iph_inner.tot_len) + + sizeof(h_outer.l4hdr.udp) + + l2_len); + break; + case IPPROTO_IPIP: + case IPPROTO_IPV6: + break; + default: + return TC_ACT_OK; + } + + /* add L2 encap (if specified) */ + switch (l2_proto) { + case ETH_P_MPLS_UC: + *((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label; + break; + case ETH_P_TEB: + if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen, + ETH_HLEN)) + return TC_ACT_SHOT; + break; + } + olen += l2_len; + + /* add room between mac and network header */ + if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags)) + return TC_ACT_SHOT; + + /* prepare new outer network header */ + h_outer.ip = iph_inner; + h_outer.ip.tot_len = bpf_htons(olen + + bpf_ntohs(h_outer.ip.tot_len)); + h_outer.ip.protocol = encap_proto; + + set_ipv4_csum((void *)&h_outer.ip); + + /* store new outer network header */ + if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen, + BPF_F_INVALIDATE_HASH) < 0) + return TC_ACT_SHOT; + + /* if changing outer proto type, update eth->h_proto */ + if (encap_proto == IPPROTO_IPV6) { + struct ethhdr eth; + + if (bpf_skb_load_bytes(skb, 0, ð, sizeof(eth)) < 0) + return TC_ACT_SHOT; + eth.h_proto = bpf_htons(ETH_P_IP); + if (bpf_skb_store_bytes(skb, 0, ð, sizeof(eth), 0) < 0) + return TC_ACT_SHOT; + } + + return TC_ACT_OK; +} + +static __always_inline int encap_ipv6(struct __sk_buff *skb, __u8 encap_proto, + __u16 l2_proto) +{ + __u16 udp_dst = UDP_PORT; + struct ipv6hdr iph_inner; + struct v6hdr h_outer; + struct tcphdr tcph; + int olen, l2_len; + __u16 tot_len; + __u64 flags; + + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_inner, + sizeof(iph_inner)) < 0) + return TC_ACT_OK; + + /* filter only packets we want */ + if (bpf_skb_load_bytes(skb, ETH_HLEN + sizeof(iph_inner), + &tcph, sizeof(tcph)) < 0) + return TC_ACT_OK; + + if (tcph.dest != __bpf_constant_htons(cfg_port)) + return TC_ACT_OK; + + olen = sizeof(h_outer.ip); + l2_len = 0; + + flags = BPF_F_ADJ_ROOM_FIXED_GSO | BPF_F_ADJ_ROOM_ENCAP_L3_IPV6; + + switch (l2_proto) { + case ETH_P_MPLS_UC: + l2_len = sizeof(mpls_label); + udp_dst = MPLS_OVER_UDP_PORT; + break; + case ETH_P_TEB: + l2_len = ETH_HLEN; + udp_dst = ETH_OVER_UDP_PORT; + break; + } + flags |= BPF_F_ADJ_ROOM_ENCAP_L2(l2_len); + + switch (encap_proto) { + case IPPROTO_GRE: + flags |= BPF_F_ADJ_ROOM_ENCAP_L4_GRE; + olen += sizeof(h_outer.l4hdr.gre); + h_outer.l4hdr.gre.protocol = bpf_htons(l2_proto); + h_outer.l4hdr.gre.flags = 0; + break; + case IPPROTO_UDP: + flags |= BPF_F_ADJ_ROOM_ENCAP_L4_UDP; + olen += sizeof(h_outer.l4hdr.udp); + h_outer.l4hdr.udp.source = __bpf_constant_htons(cfg_udp_src); + h_outer.l4hdr.udp.dest = bpf_htons(udp_dst); + tot_len = bpf_ntohs(iph_inner.payload_len) + sizeof(iph_inner) + + sizeof(h_outer.l4hdr.udp); + h_outer.l4hdr.udp.check = 0; + h_outer.l4hdr.udp.len = bpf_htons(tot_len); + break; + case IPPROTO_IPV6: + break; + default: + return TC_ACT_OK; + } + + /* add L2 encap (if specified) */ + switch (l2_proto) { + case ETH_P_MPLS_UC: + *((__u32 *)((__u8 *)&h_outer + olen)) = mpls_label; + break; + case ETH_P_TEB: + if (bpf_skb_load_bytes(skb, 0, (__u8 *)&h_outer + olen, + ETH_HLEN)) + return TC_ACT_SHOT; + break; + } + olen += l2_len; + + /* add room between mac and network header */ + if (bpf_skb_adjust_room(skb, olen, BPF_ADJ_ROOM_MAC, flags)) + return TC_ACT_SHOT; + + /* prepare new outer network header */ + h_outer.ip = iph_inner; + h_outer.ip.payload_len = bpf_htons(olen + + bpf_ntohs(h_outer.ip.payload_len)); + + h_outer.ip.nexthdr = encap_proto; + + /* store new outer network header */ + if (bpf_skb_store_bytes(skb, ETH_HLEN, &h_outer, olen, + BPF_F_INVALIDATE_HASH) < 0) + return TC_ACT_SHOT; + + return TC_ACT_OK; +} + +SEC("encap_ipip_none") +int __encap_ipip_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_IPIP, ETH_P_IP); + else + return TC_ACT_OK; +} + +SEC("encap_gre_none") +int __encap_gre_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_GRE, ETH_P_IP); + else + return TC_ACT_OK; +} + +SEC("encap_gre_mpls") +int __encap_gre_mpls(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_GRE, ETH_P_MPLS_UC); + else + return TC_ACT_OK; +} + +SEC("encap_gre_eth") +int __encap_gre_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_GRE, ETH_P_TEB); + else + return TC_ACT_OK; +} + +SEC("encap_udp_none") +int __encap_udp_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_UDP, ETH_P_IP); + else + return TC_ACT_OK; +} + +SEC("encap_udp_mpls") +int __encap_udp_mpls(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_UDP, ETH_P_MPLS_UC); + else + return TC_ACT_OK; +} + +SEC("encap_udp_eth") +int __encap_udp_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IP)) + return encap_ipv4(skb, IPPROTO_UDP, ETH_P_TEB); + else + return TC_ACT_OK; +} + +SEC("encap_sit_none") +int __encap_sit_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv4(skb, IPPROTO_IPV6, ETH_P_IP); + else + return TC_ACT_OK; +} + +SEC("encap_ip6tnl_none") +int __encap_ip6tnl_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_IPV6, ETH_P_IPV6); + else + return TC_ACT_OK; +} + +SEC("encap_ip6gre_none") +int __encap_ip6gre_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_GRE, ETH_P_IPV6); + else + return TC_ACT_OK; +} + +SEC("encap_ip6gre_mpls") +int __encap_ip6gre_mpls(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_GRE, ETH_P_MPLS_UC); + else + return TC_ACT_OK; +} + +SEC("encap_ip6gre_eth") +int __encap_ip6gre_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_GRE, ETH_P_TEB); + else + return TC_ACT_OK; +} + +SEC("encap_ip6udp_none") +int __encap_ip6udp_none(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_UDP, ETH_P_IPV6); + else + return TC_ACT_OK; +} + +SEC("encap_ip6udp_mpls") +int __encap_ip6udp_mpls(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_UDP, ETH_P_MPLS_UC); + else + return TC_ACT_OK; +} + +SEC("encap_ip6udp_eth") +int __encap_ip6udp_eth(struct __sk_buff *skb) +{ + if (skb->protocol == __bpf_constant_htons(ETH_P_IPV6)) + return encap_ipv6(skb, IPPROTO_UDP, ETH_P_TEB); + else + return TC_ACT_OK; +} + +static int decap_internal(struct __sk_buff *skb, int off, int len, char proto) +{ + char buf[sizeof(struct v6hdr)]; + struct gre_hdr greh; + struct udphdr udph; + int olen = len; + + switch (proto) { + case IPPROTO_IPIP: + case IPPROTO_IPV6: + break; + case IPPROTO_GRE: + olen += sizeof(struct gre_hdr); + if (bpf_skb_load_bytes(skb, off + len, &greh, sizeof(greh)) < 0) + return TC_ACT_OK; + switch (bpf_ntohs(greh.protocol)) { + case ETH_P_MPLS_UC: + olen += sizeof(mpls_label); + break; + case ETH_P_TEB: + olen += ETH_HLEN; + break; + } + break; + case IPPROTO_UDP: + olen += sizeof(struct udphdr); + if (bpf_skb_load_bytes(skb, off + len, &udph, sizeof(udph)) < 0) + return TC_ACT_OK; + switch (bpf_ntohs(udph.dest)) { + case MPLS_OVER_UDP_PORT: + olen += sizeof(mpls_label); + break; + case ETH_OVER_UDP_PORT: + olen += ETH_HLEN; + break; + } + break; + default: + return TC_ACT_OK; + } + + if (bpf_skb_adjust_room(skb, -olen, BPF_ADJ_ROOM_MAC, + BPF_F_ADJ_ROOM_FIXED_GSO)) + return TC_ACT_SHOT; + + return TC_ACT_OK; +} + +static int decap_ipv4(struct __sk_buff *skb) +{ + struct iphdr iph_outer; + + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_outer, + sizeof(iph_outer)) < 0) + return TC_ACT_OK; + + if (iph_outer.ihl != 5) + return TC_ACT_OK; + + return decap_internal(skb, ETH_HLEN, sizeof(iph_outer), + iph_outer.protocol); +} + +static int decap_ipv6(struct __sk_buff *skb) +{ + struct ipv6hdr iph_outer; + + if (bpf_skb_load_bytes(skb, ETH_HLEN, &iph_outer, + sizeof(iph_outer)) < 0) + return TC_ACT_OK; + + return decap_internal(skb, ETH_HLEN, sizeof(iph_outer), + iph_outer.nexthdr); +} + +SEC("decap") +int decap_f(struct __sk_buff *skb) +{ + switch (skb->protocol) { + case __bpf_constant_htons(ETH_P_IP): + return decap_ipv4(skb); + case __bpf_constant_htons(ETH_P_IPV6): + return decap_ipv6(skb); + default: + /* does not match, ignore */ + return TC_ACT_OK; + } +} + +char __license[] SEC("license") = "GPL"; |